The skin element has a first surface, a second surface, which is located opposite the first surface, a circumferential edge and a center axis. As such, of the first and second surface, the one surface is oriented towards the pressure side, which is to say, towards the cabin or, respectively, the pressurized cabin, and the other surface is oriented away from the cabin, towards the tail section of the aircraft fuselage. The edge is connected to the aircraft fuselage structure, in which the pressure bulkhead is inserted or is to be inserted, or, respectively, the edge is adapted to the inner circumference of the fuselage structure. The center axis extends approximately perpendicular to the first and second surface and extends parallel to, or approximately parallel to, a longitudinal axis of the aircraft fuselage.
The reinforcement assembly has a plurality of radially disposed reinforcement elements, which extend along the first surface of the skin element and, resting against the skin element, extend in a radial direction between an outer end at the edge of the skin element and an inner end, which faces the center axis. The inner end is thus the end of the radially disposed reinforcement elements, which is closest to the center axis. As such, the inner end may lie on the center axis, for example, as may be the case when a plurality of radially disposed reinforcement elements are connected to one another at the inner ends thereof. A passage opening may be provided in the skin element between the inner ends of the radially disposed reinforcement elements and the center axis, through which opening systems, for example such as cables and hoses or pipes, can be run from the cabin into the tail section.
As viewed in a cross section, which extends radially along the center axis, which is to say, between the outer and inner ends of the radially disposed reinforcement elements, each of the radially disposed reinforcement elements defines a first contour line, and defines a second contour line, which is located opposite the first contour line. In so doing, each contour line extends from the outer end of the radially disposed reinforcement elements, to the inner end thereof. At the same time, the contour lines form outer boundary lines of the radially disposed reinforcement elements. The reinforcement assembly, which is to say, the radially disposed reinforcement elements, rests with the first contour lines thereof on the first surface of the skin element. At the same time, no additional skin element rests along the second contour lines on the reinforcement assembly.
Some pressure bulkheads of this kind, or similar thereto, are known from the prior art. In the case of the pressure bulkhead currently in common use, the skin element, together with the reinforcement elements affixed thereto, have a pronounced, dome-shaped curvature in order to be able to best absorb the pressure load between the cabin pressure and the ambient pressure to which the pressure bulkhead is exposed. As such, the reinforcement elements are disposed in a radial manner on the convex surface of the skin element, wherein the reinforcement elements have a constant thickness along the entire course thereof, which is to say, the distance between the first and second contour line of the elements does not change, whereby the first and second contour lines extend such that they are substantially parallel to one another. The disadvantage with such pressure bulkhead configurations, however, is that on the one hand, the pressure bulkhead takes up a great deal of space due to the pronounced curvature thereof, wherein the space within the curvature is normally not used, for reasons of safety, and on the other hand, the manufacture of the pressure bulkhead as a fiber composite work piece is very complex, since disposing and affixing the reinforcement elements to the convex skin element is very complex.
For this reason, there have been various attempts in the prior art to produce a pressure bulkhead that is not convex, the skin elements of which thus extend in a plane, having no curvature or only an extremely slight curvature.
A pressure bulkhead of this kind, which lacks a curvature, is described in U.S. Pat. No. 6,443,392 B1, which has a flat skin element, which is supported circumferentially along the edge, as well as being supported toward the middle thereof, vis-à-vis the fuselage structure, by a plurality of support members. A pressure bulkhead having such a design requires a large number of components, however, and in particular, reinforcement elements, all of which must be assembled and which involve an undesirable, heavy weight.
Another alternative for a pressure bulkhead having a cross section that has no curvature, is known from US 2009/0242701 A1, wherein a flat skin element is supported by a framework comprising reinforcement elements, which extend perpendicular to one another. A pressure bulkhead having a similar design is also known from US 2014/0124622 A1. In practice, however, such a configuration of the pressure bulkhead has various disadvantages, in particular, increased complexity in the assembly thereof, as well as an undesirable, heavy weight.
A pressure bulkhead having a sandwich construction is known from DE 10 2012 005 451 A1, wherein two skin elements, which are located opposite one another, have a slight curvature in the form of a lens, and hold a foam core between them. Although the lens-shaped cross section has proven to be advantageous with respect to the structural load, which is to say that, due to this construction, the pressure loads can be absorbed and transferred both well and easily, and with a comparatively lightweight design, in the case of a pressure bulkhead having a sandwich construction, which is to say, a construction sealed between two skin elements, it is disadvantageous that the core cannot be easily examined, for example for routine inspections.
Finally, a pressure bulkhead is known from DE 10 2010 018 933 A1, which discloses a flat skin element and a plurality of reinforcement elements, which extend radially, and which rest on the first surface of the skin element. On the side facing away from the skin element, the reinforcement elements have a first contour line, which rises in sections from the center axis, wherein the distance between the first contour line and the second contour line, which rests against the skin element, increases. It has been found, however, that such a discontinuous course of the first contour line, which progresses in sections, does not allow for pressure loads to be optimally absorbed or, respectively, transferred to the fuselage structure. This, in turn has the consequence that the pressure bulkhead must be dimensioned in order to absorb the loads that occur, such that an undesirably large amount of material must be used, and in consequence, this also results in an undesirable, heavy weight.